NNIN
Nanotechnology Education
Teacher’s Preparatory Guide
Scale Models
Overview: This activity gives students a sense of size and scale using objects that cannot be seen
with the naked eye. This activity focuses on measuring length, for this is the most common
feature when presenting nanoscale structures or nanoscale science. Understanding size and scale
is fundamental to learning about nanotechnology as size defines the nanoscale (1-100nm in one
dimension). Size is often divided into scales – macro, micro, nano and atomic. Helping students
understand these “worlds” is an important part of their science knowledge and will help them to
understand the relatively small size of the nanoscale. It can be introduced into the K–12
curriculum by discussing scientific measurement. This activity connects well to the introduction
of atoms and cell structures as well as advancements in technology.
Purpose: This activity is designed to help students understand the size and scale of objects.
Time Required: ~15 minutes
Level: Elementary, middle school, and high school; general science, life science, mathematics
Big Idea: Size and Scale
Teacher Background: Students often have trouble understanding size and scale in science, due
to the different measurement units taught (metric and English), the different types of units used
for length and volume, and the lack of consistent practice through their educational career. These
lessons present size and scale to students from kindergarten to high school. Common student
misconceptions1 include:
 mixing units such as centimeters and inches
 not realizing the connection between relative and absolute sizes of two objects
 the inability to use measurement tools accurately
 believing that objects that cannot be seen with the naked eye are approximately the same size
This lesson introduces scale by demonstrating scales as factors of ten. This facilitates the
introduction and reinforcement of the metric scale and paves the way to the discussion of lengths
that are smaller than what can be seen with the naked eye. The lesson also introduces the concept
of using different tools to address different length scales. A commonly used ruler gives way to
the microscope, which eventually gives way to the scanning electron microscope (SEM) and the
atomic force microscope (AFM) when observing lengths that shrink to the nanoscale.
Source:
1. Stevens, S., Sutherland, L., Krajcik, J., The Big Ideas of Nanoscale Science and Engineering.
NSTA Press, 2009.
National Nanotechnology Infrastructure Network
www.nnin.org
Copyright©2011 Marilyn Garza and the University of California Santa Barbara
Permission granted for printing and copying for local classroom use without modification
Development and distribution partially funded by the National Science Foundation
NNIN Document: NNIN 1276
REV: 08/2012
Page 1
Materials per class
 drawing of a cell or an ant that is 1 meter
in diameter on butcher paper or project
an image onto a screen
 masking tape (to hang the drawing on
the wall)
 meter stick
Materials per student
 clay or Play-Doh, at least 1 cubic inch
 metric rulers
 colored pencils
Advance Preparation: Acquire butcher paper and colored pencils at a craft supply store.
Alternatively, you can find a picture of a cell online, and either print as transparency and use
with an overhead, or print and use with a document camera. Purchase play dough or clay, which
may be found at a craft store. Play-Doh sells mini canisters of their product in packs of ten. This
product may facilitate material logistics. Alternatively, you can make your own play dough by
using a recipe at this link: http://www.playdoughrecipe.com
Advance Preparation for
Kindergarten–2nd grade
1. Draw an ant that is 1 meter long on butcher
paper. An average ant is about 3 mm long,
so the scale you will use is 3 mm:1 m.
2. Calculate your height (or any other object)
to give the children a new frame of
reference by using this formula:
Advance Preparation for
Grades 3–12
1. Draw a cell that is 1 meter in diameter on
butcher paper or project an image of a cell
onto a screen. The average animal cell is
10m in diameter, so the scale you will
use is 10 m:1 m.
length of the object in meters  1000  3 =
scaled length in meters
The result will be the scaled length of the
object in meters (as compared to your
meter-long ant).
Example: A student is 1.1 meters tall. To
calculate her scaled height as compared to the
meter long ant:
Step 1: 1.1 meters  1000 mm/m= 1100 mm
Step 2: 1100 mm  3 = 366.7 scaled meters
An example of a meter-sized cell.
2. Calculate your height as well as other items
within this scale for interest.
Example: If a person is 1.5 meters tall:
So if an ant were enlarged to a length of 1
meter, and the student increased by the same
amount as the ant, the student would stand
approximately 367 meters tall.
Step 1: 1.5 m  1,000,000 m/m= 1,500,000 m
Step 2: 1,500,000 m  10 = 150,000 scaled
meters or 150 km!
For height comparison:
Kindergarten–Grade 2
Height of a basketball hoop
3m
Ten story building
~ 30 m
Statue of Liberty
50 m
Length of a football field
91.44 m
Grades 3–12
Mount Everest
Space shuttle orbits
Aurora
~ 9 km
320 – 390 km
100 km
National Nanotechnology Infrastructure Network
www.nnin.org
Copyright©2011 Marilyn Garza and the University of California Santa Barbara
Permission granted for printing and copying for local classroom use without modification
Development and distribution partially funded by the National Science Foundation
Page 2
Other interesting objects to mention may be:
Object
Thickness of cell membrane
Transistor Gate
Glucose molecule
Width of DNA strand
Actual length
10 nm
90 nm
1 nm
0.25 nm
Scaled length
10 mm
9 mm
0.1 mm
0.25 mm
Safety Information: None. Tell students not to eat the clay or play dough.
Teaching Strategies:
Kindergarten–Grade 2
Grades 3–12
1. Ask students to think of objects that are
small. Ask students, “How big is a cell of a
normal ant?” Students will soon learn that
all living things are made of cells, but
many students are often confused about
how big a cell is and will confuse a cell
with organs or tissue.
2. Present the poster of the scaled ant.
Explain that the ant has now grown to be a
meter long.
3. To provide a frame of reference, give an
example of how tall you would be if you
were to increase in size by the same scale.
4. Distribute play dough to each student. Ask
students to show the size of a cell of this
scaled ant, using the play dough. Give
students a fair amount of play dough to
fairly assess the student’s concept of scale.
When all the students are done, have them
share their “model” with two other
students. Allow students to form their piece
of play dough without outside input.
Encourage them to share and present their
justifications orally and/or on paper.
5. Share results as a class to assess the range
of sizes that students came up with and
encourage students to justify their answers.
6. Share the scaled length of a cell of a metersized ant (3 mm). Have students use their
rulers to measure and correct their model.
1. Ask students to think of objects that are
small. Present the poster of the scaled cell.
Explain that the cell has been increased to
be a meter in length. Review where cells
are found, the function of the cell, and
perhaps the functions of various parts of
the cell.
2. To provide a frame of reference, give an
example of how tall you would be if you
were to increase in size by the same scale.
3. Distribute play dough to each student and
ask students to demonstrate the width of a
DNA strand in this scaled cell using the
play dough. Have them share their model
with two other students. Share results as a
class to assess the range of sizes that
students came up with and encourage
students to justify their answers.
4. Explain the scaled length of the width of a
strand of DNA (0.025 mm/2.5nm). Have
students use their rulers to measure and
correct their scale model.
An example
of the size
of clay
piece that is
0.25 mm.
It’s small!
For reinforcement: If possible, keep the large ant or cell poster and a sample play dough piece
out and visible in the classroom for the rest of the unit as reinforcement.
Cleanup: Collect play dough in canisters.
National Nanotechnology Infrastructure Network
www.nnin.org
Copyright©2011 Marilyn Garza and the University of California Santa Barbara
Permission granted for printing and copying for local classroom use without modification
Development and distribution partially funded by the National Science Foundation
Page 3
Assessment:
Students should understand the concept of scaled models and how they can be used to more
easily comprehend relationships in size. For example, a student should be able to calculate the
scaled height of their chair, given the scale model of the ant or cell.
National Science Education Standards (Grades K–4)
Content Standard B: Physical Science
 Properties of objects and materials
Content Standard E: Science and Technology
 Understandings about science and technology
 Abilities to distinguish between natural objects and objects made by humans
National Science Education Standards (Grades 5–8)
Content Standard B: Physical Science
 Properties and changes of properties in matter
Content Standard E: Science and Technology
 Understandings about science and technology
National Science Education Standards (Grades 9–12)
Content Standard B: Physical Science
 Structure and properties of matter
Content Standard E: Science and Technology
 Understandings about science and technology
Principles and Standards for School Mathematics
Measurement
 Understand measurable attributes of objects and the units, systems, and processes
of measurement
 Apply appropriate techniques, tools, and formulas to determine measurements
Numbers and Operation
 Understand numbers, ways of representing numbers, relationships among
numbers, and number systems
 Compute fluently and make reasonable estimates
National Nanotechnology Infrastructure Network
www.nnin.org
Copyright©2011 Marilyn Garza and the University of California Santa Barbara
Permission granted for printing and copying for local classroom use without modification
Development and distribution partially funded by the National Science Foundation
Page 4